My simple goal is to fade animate hiding and showing functions.
Button.hidden = YES;
Simple enough. However, is it possible to have it fade out rather than just disappearing? It looks rather unprofessional that way.
This question is related to
ios
objective-c
uiviewanimation
swift 4.2
with extension :
extension UIView {
func hideWithAnimation(hidden: Bool) {
UIView.transition(with: self, duration: 0.5, options: .transitionCrossDissolve, animations: {
self.isHidden = hidden
})
}
}
simple method:
func setView(view: UIView, hidden: Bool) {
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.isHidden = hidden
})
}
UIView.transition(with:) function is nice and neat.
Many have posted it but none has noticed there lies a fault will show up only when you run it.
You can transition hidden property to true perfectly, whereas when you attempt to transition it to false, the view will simple disappear suddenly without any animation.
That's because this api only works within a view, which means when you transition a view to show, in fact itself shows immediately, only its content animated out gradually.
When you try to hide this view, itself hide right away, makes the animation to its content meaningless.
To solve this, when hiding a view, the transition target should be its parent view instead of the view you want to hide.
func transitionView(_ view: UIView?, show: Bool, completion: BoolFunc? = nil) {
guard let view = view, view.isHidden == show, let parent = view.superview else { return }
let target: UIView = show ? view : parent
UIView.transition(with: target, duration: 0.4, options: [.transitionCrossDissolve], animations: {
view.isHidden = !show
}, completion: completion)
}
I created category for UIView for this purpose and implemented a special little bit different concept: visibility. The main difference of my solution is that you can call [view setVisible:NO animated:YES] and right after that synchronously check [view visible] and get correct result. This is pretty simple but extremely useful.
Besides, it is allowed to avoid using "negative boolean logic" (see Code Complete, page 269, Use positive boolean variable names for more information).
UIView+Visibility.swift
import UIKit
private let UIViewVisibilityShowAnimationKey = "UIViewVisibilityShowAnimationKey"
private let UIViewVisibilityHideAnimationKey = "UIViewVisibilityHideAnimationKey"
private class UIViewAnimationDelegate: NSObject {
weak var view: UIView?
dynamic override func animationDidStop(animation: CAAnimation, finished: Bool) {
guard let view = self.view where finished else {
return
}
view.hidden = !view.visible
view.removeVisibilityAnimations()
}
}
extension UIView {
private func removeVisibilityAnimations() {
self.layer.removeAnimationForKey(UIViewVisibilityShowAnimationKey)
self.layer.removeAnimationForKey(UIViewVisibilityHideAnimationKey)
}
var visible: Bool {
get {
return !self.hidden && self.layer.animationForKey(UIViewVisibilityHideAnimationKey) == nil
}
set {
let visible = newValue
guard self.visible != visible else {
return
}
let animated = UIView.areAnimationsEnabled()
self.removeVisibilityAnimations()
guard animated else {
self.hidden = !visible
return
}
self.hidden = false
let delegate = UIViewAnimationDelegate()
delegate.view = self
let animation = CABasicAnimation(keyPath: "opacity")
animation.fromValue = visible ? 0.0 : 1.0
animation.toValue = visible ? 1.0 : 0.0
animation.fillMode = kCAFillModeForwards
animation.removedOnCompletion = false
animation.delegate = delegate
self.layer.addAnimation(animation, forKey: visible ? UIViewVisibilityShowAnimationKey : UIViewVisibilityHideAnimationKey)
}
}
func setVisible(visible: Bool, animated: Bool) {
let wereAnimationsEnabled = UIView.areAnimationsEnabled()
if wereAnimationsEnabled != animated {
UIView.setAnimationsEnabled(animated)
defer { UIView.setAnimationsEnabled(!animated) }
}
self.visible = visible
}
}
UIView+Visibility.h
#import <UIKit/UIKit.h>
@interface UIView (Visibility)
- (BOOL)visible;
- (void)setVisible:(BOOL)visible;
- (void)setVisible:(BOOL)visible animated:(BOOL)animated;
@end
UIView+Visibility.m
#import "UIView+Visibility.h"
NSString *const UIViewVisibilityAnimationKeyShow = @"UIViewVisibilityAnimationKeyShow";
NSString *const UIViewVisibilityAnimationKeyHide = @"UIViewVisibilityAnimationKeyHide";
@implementation UIView (Visibility)
- (BOOL)visible
{
if (self.hidden || [self.layer animationForKey:UIViewVisibilityAnimationKeyHide]) {
return NO;
}
return YES;
}
- (void)setVisible:(BOOL)visible
{
[self setVisible:visible animated:NO];
}
- (void)setVisible:(BOOL)visible animated:(BOOL)animated
{
if (self.visible == visible) {
return;
}
[self.layer removeAnimationForKey:UIViewVisibilityAnimationKeyShow];
[self.layer removeAnimationForKey:UIViewVisibilityAnimationKeyHide];
if (!animated) {
self.alpha = 1.f;
self.hidden = !visible;
return;
}
self.hidden = NO;
CGFloat fromAlpha = visible ? 0.f : 1.f;
CGFloat toAlpha = visible ? 1.f : 0.f;
NSString *animationKey = visible ? UIViewVisibilityAnimationKeyShow : UIViewVisibilityAnimationKeyHide;
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
animation.duration = 0.25;
animation.fromValue = @(fromAlpha);
animation.toValue = @(toAlpha);
animation.delegate = self;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[self.layer addAnimation:animation forKey:animationKey];
}
#pragma mark - CAAnimationDelegate
- (void)animationDidStop:(CAAnimation *)animation finished:(BOOL)finished
{
if ([[self.layer animationForKey:UIViewVisibilityAnimationKeyHide] isEqual:animation]) {
self.hidden = YES;
}
}
@end
Swift 4
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
self.alpha = 0.0
}) { (completed) in
self.isHidden = true
completion(true)
}
}
}
And to use use it, simple call these functions like:
yourView.fadeOut() // this will hide your view with animation
yourView.fadeIn() /// this will show your view with animation
You can try this.
func showView(objView:UIView){
objView.alpha = 0.0
UIView.animate(withDuration: 0.5, animations: {
objView.alpha = 0.0
}, completion: { (completeFadein: Bool) -> Void in
objView.alpha = 1.0
let transition = CATransition()
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.type = kCATransitionFade
objView.layer.add(transition, forKey: nil)
})
}
func HideView(objView:UIView){
UIView.animate(withDuration: 0.5, animations: {
objView.alpha = 1.0
}, completion: { (completeFadein: Bool) -> Void in
objView.alpha = 0.0
let transition = CATransition()
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.type = kCATransitionFade
objView.layer.add(transition, forKey: nil)
})
}
And pass your view name
showView(objView: self.viewSaveCard)
HideView(objView: self.viewSaveCard)
UIView.transition(with: title3Label, duration: 0.4,
options: .transitionCrossDissolve,
animations: {
self.title3Label.isHidden = !self.title3Label.isHidden
})
Applying transition on View with some delay gives hide and show effect
My solution for Swift 3. So, I created the function, that hide/unhide view in the right order(when hiding - set alpha to 0 and then isHidden to true; unhiding - first reveal the view and then set it's alpha to 1):
func hide(_ hide: Bool) {
let animations = hide ? { self.alpha = 0 } :
{ self.isHidden = false }
let completion: (Bool) -> Void = hide ? { _ in self.isHidden = true } :
{ _ in UIView.animate(withDuration: duration, animations: { self.alpha = 1 }) }
UIView.animate(withDuration: duration, animations: animations, completion: completion)
}
Swift 3
func appearView() {
self.myView.alpha = 0
self.myView.isHidden = false
UIView.animate(withDuration: 0.9, animations: {
self.myView.alpha = 1
}, completion: {
finished in
self.myView.isHidden = false
})
}
Swift 4 Transition
UIView.transition(with: view, duration: 3, options: .transitionCurlDown,
animations: {
// Animations
view.isHidden = hidden
},
completion: { finished in
// Compeleted
})
If you use the approach for older swift versions you'll get an error :
Cannot convert value of type '(_) -> ()' to expected argument type '(() -> Void)?'
Useful reference.
Use this solution for a smooth fadeOut and fadeIn effects
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseOut, animations: {
self.isHidden = true
self.alpha = 0.0
}, completion: completion)
}
}
usage is as like
uielement.fadeIn()
uielement.fadeOut()
Thanks
To fade out:
Objective-C
[UIView animateWithDuration:0.3 animations:^{
button.alpha = 0;
} completion: ^(BOOL finished) {//creates a variable (BOOL) called "finished" that is set to *YES* when animation IS completed.
button.hidden = finished;//if animation is finished ("finished" == *YES*), then hidden = "finished" ... (aka hidden = *YES*)
}];
Swift 2
UIView.animateWithDuration(0.3, animations: {
button.alpha = 0
}) { (finished) in
button.hidden = finished
}
Swift 3, 4, 5
UIView.animate(withDuration: 0.3, animations: {
button.alpha = 0
}) { (finished) in
button.isHidden = finished
}
To fade in:
Objective-C
button.alpha = 0;
button.hidden = NO;
[UIView animateWithDuration:0.3 animations:^{
button.alpha = 1;
}];
Swift 2
button.alpha = 0
button.hidden = false
UIView.animateWithDuration(0.3) {
button.alpha = 1
}
Swift 3, 4, 5
button.alpha = 0
button.isHidden = false
UIView.animate(withDuration: 0.3) {
button.alpha = 1
}
isHidden is an immediate value and you cannot affect an animation on it, instead of this you can use Alpha for hide your view
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.alpha = 0
})
And for showing:
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.alpha = 1
})
If your view is set to hidden by default or you change the Hidden state which I think you should in many cases, then none of the approaches in this page will give you both FadeIn/FadeOut animation, it will only animate one of these states, the reason is you are setting the Hidden state to false before calling UIView.animate method which will cause a sudden visibility and if you only animate the alpha then the object space is still there but it's not visible which will result to some UI issues.
So the best approach is to check first if the view is hidden then set the alpha to 0.0, like this when you set the Hidden state to false you won't see a sudden visibility.
func hideViewWithFade(_ view: UIView) {
if view.isHidden {
view.alpha = 0.0
}
view.isHidden = false
UIView.animate(withDuration: 0.3, delay: 0.0, options: .transitionCrossDissolve, animations: {
view.alpha = view.alpha == 1.0 ? 0.0 : 1.0
}, completion: { _ in
view.isHidden = !Bool(truncating: view.alpha as NSNumber)
})
}
You can do it VERY easily using Animatics library:
//To hide button:
AlphaAnimator(0) ~> button
//to show button
AlphaAnimator(1) ~> button
UIView animated properties are:
- frame
- bounds
- center
- transform
- alpha
- backgroundColor
- contentStretch
Describe in: Animations
isHidden is not one of them, so as I see it the best way is:
Swift 4:
func setView(view: UIView, hidden: Bool) {
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.isHidden = hidden
})
}
Objective C:
- (void)setView:(UIView*)view hidden:(BOOL)hidden {
[UIView transitionWithView:view duration:0.5 options:UIViewAnimationOptionTransitionCrossDissolve animations:^(void){
[view setHidden:hidden];
} completion:nil];
}
I use this little Swift 3 extension:
extension UIView {
func fadeIn(duration: TimeInterval = 0.5,
delay: TimeInterval = 0.0,
completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
UIView.animate(withDuration: duration,
delay: delay,
options: UIViewAnimationOptions.curveEaseIn,
animations: {
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5,
delay: TimeInterval = 0.0,
completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
UIView.animate(withDuration: duration,
delay: delay,
options: UIViewAnimationOptions.curveEaseIn,
animations: {
self.alpha = 0.0
}, completion: completion)
}
}
func flipViews(fromView: UIView, toView: UIView) {
toView.frame.origin.y = 0
self.view.isUserInteractionEnabled = false
UIView.transition(from: fromView, to: toView, duration: 0.5, options: .transitionFlipFromLeft, completion: { finished in
fromView.frame.origin.y = -900
self.view.isUserInteractionEnabled = true
})
}
Tried some of the exited answers, some only work for one situation, some of them need to add two functions.
Option 1
Nothing to do with view.isHidden.
extension UIView {
func animate(fadeIn: Bool, withDuration: TimeInterval = 1.0) {
UIView.animate(withDuration: withDuration, delay: 0.0, options: .curveEaseInOut, animations: {
self.alpha = fadeIn ? 1.0 : 0.0
})
}
}
Then pass isFadeIn (true or false)
view.animate(fadeIn: isFadeIn)
Option 2
Don't pass any parameter. It fades in or out according to isUserInteractionEnabled. This also suits the situation animate back and forth very well.
func animateFadeInOut(withDuration: TimeInterval = 1.0) {
self.isUserInteractionEnabled = !self.isUserInteractionEnabled
UIView.animate(withDuration: withDuration, delay: 0.0, options: .curveEaseInOut, animations: {
self.alpha = self.isUserInteractionEnabled ? 1.0 : 0.0
})
}
Then you call
yourView.animateFadeInOut()
Why
self.isUserInteractionEnabled?Tried to replace
self.isUserInteractionEnabledbyself.isHidden, no luck at all.
That's it. Cost me sometime, hope it helps someone.
the code of @Umair Afzal working fine in swift 5 after some changes
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.alpha = 0.0
}) { (completed) in
self.isHidden = true
completion(true)
}
}
}
for use
yourView.fadeOut()
yourView.fadeIn()
Swift 5.0, with generics:
func hideViewWithAnimation<T: UIView>(shouldHidden: Bool, objView: T) {
if shouldHidden == true {
UIView.animate(withDuration: 0.3, animations: {
objView.alpha = 0
}) { (finished) in
objView.isHidden = shouldHidden
}
} else {
objView.alpha = 0
objView.isHidden = shouldHidden
UIView.animate(withDuration: 0.3) {
objView.alpha = 1
}
}
}
Use:
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountLabelBGView)
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountLabel)
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountButton)
Here itemCountLabelBGView is a UIView, itemCountLabel is a UILabel & itemCountButton is a UIButton, So it will work for every view object whose parent class is UIView.
This code give an animation like pushing viewController in uinavigation controller...
CATransition *animation = [CATransition animation];
animation.type = kCATransitionPush;
animation.subtype = kCATransitionFromRight;
animation.duration = 0.3;
[_viewAccountName.layer addAnimation:animation forKey:nil];
_viewAccountName.hidden = true;
Used this for pop animation...
CATransition *animation = [CATransition animation];
animation.type = kCATransitionPush;
animation.subtype = kCATransitionFromLeft;
animation.duration = 0.3;
[_viewAccountName.layer addAnimation:animation forKey:nil];
_viewAccountName.hidden = false;
Source: Stackoverflow.com